You are a star Nish, and bring so much light into other people's lives. Diana, Princess of Wales, 1997 Dr Nish Joshi comes with so many ringing endorsements I feel I've got tinnitus. Here's Patsy Kensit - "Joshi is a miracle worker." And Sadie Frost - "You completely trust yourself with Joshi. He's an amazing man." And Gwyneth Paltrow - "Joshi is truly special. I love him." Perhaps the best endorsement comes from Dr Joshi himself, on the back of his how-to book, in big green type - "If no one comments within two weeks on how great you're looking, you must be cheating." He is an increasing presence in newspapers and celebrity magazines. The medical guru of the rich and famous has become rich and famous himself. His book, Dr Joshi's Holistic Detox: 21 Days To A Healthier, Slimmer You - For Life (Hodder Mobius), is a bestseller. So how effective is it, and what's the secret of his success? That's what I'm here to find out.

The woman in the reception gives me a form to fill in. I have to tick various aches and pains and chronic conditions. I find myself ticking almost everything. Headaches? Yes. Aching muscles? Yes. Sweating? Yes. Irritability? Yes. Colds and infections. Yes? Dry skin? Yes. Sore eyes. Yes, yes, yes, yes. The list is like the Penny Purse, the more I fill in, the more it seems to replenish itself. Strange, I have never thought of myself as unhealthy.

Dr Joshi passes as I'm form filling. He's got a lovely smile, clear brown eyes and a soft voice. He looks like an Asian Elton John. I can see why he would have appealed to Princess Di. He disappears to a room downstairs, and I continue ticking his boxes. I'm beginning to feel like a hopeless case, not long for this world. The receptionist looks at her watch. Have I completed the forms? No. Two minutes later she asks again. No, I say."Well, if I were you, I'd just go up. It doesn't matter if you've not finished."

I suppose I'm an obvious candidate for detox. I'm not an alcoholic or drug addict, but I do have lots of toxins running through my body. I drink a fair amount of booze, oceans of coffee, eat a ridiculous amount of chocolate, drink loads of milk, love my potatoes and pastas and stodge, and smoke.

Dr Joshi weighs me. I'm pleasantly surprised - 13 stone with a few clothes on (I'm 5ft 11ins). He takes my pulse, my blood pressure, checks my eyes and mouth. "You're very mucusy," he says. "You've got a lot of mucus. A lot of dampness." I'm not sure whether it's a compliment. He sits me down, checks my incomplete notes and asks me to tell him about myself. I say that work is important to me, I get annoyed if I don't do it well, that I don't have specific goals in life, I have a compulsive personality, am a depressive and have nightmares. He looks through the notes before reaching his conclusion.

"Yes, looking at what you've ticked off here, Simon, we can see that you feel guilty when relaxing and have difficulty getting to sleep. Now that would suggest to me that you are mentally very alert, and you are driven as a human being, and when you do something, you like to do it very well." I feel as if I'm having my tea leaves read. He says I seem to be a bit below par, that there are many potential causes behind my symptoms, and he's here to find out exactly what's what. Most important, though, he wants to treat me, the person, not just simply the symptoms.

"I want to know whether the headaches you are complaining about are a result of stress, whether they are a result of muscular tension in your neck or a result of low blood-sugar levels, and if that is directly affected by your chocaholicism, and whether taking all the chocolate is making you produce too much insulin, so you're getting peaks and troughs in your blood-sugar levels, which is making you tired, which is making you want to have more coffee, which is making you more dehydrated, which is making you tired, which is making you have more chocolate, which is making you have more coffee." Which is making me dizzy.

The point of the detox diet is to cleanse the liver, which in turn is the cleanser and filter of the blood system. Toxins congest our system, slow down our metabolism, clog up our digestive tract, knacker the liver, pollute the blood, narrow and harden the arteries, and coat our muscles with nasty calcium and mineral deposits. In short, toxins are not good news. Dr Joshi reckons that after 21 days I can expect to be revitalised, replenished and one very happy bunny. "After your three-week programme," the book says, "you will have gained a real sense of achievement; finally, you are on the way to being the slimmer, healthier, brighter, more positive person that you have so often imagined yourself to be... The Detox changes your palate so that you will actually dislike the taste of those foods that are bad for you."

Most of us in the west indulge in a diet that is far too acidic, Dr Joshi says, and his detox aims to alter the pH balance to return the body to its naturally alkaline state. Acidic food (pizza, chocolate, salt, colourants, additives and alcohol full of sugar) leads to acid flowing into the muscles, which tightens them up and constricts the blood flow. The diet does allow for one acidic exception - lemons, he says, turn alkaline when combined with the juices and digestives acids already in our body.

Top Ten Detox Rules

No red meat

No dairy produce

No fruit - except bananas

No wheat, gluten, yeast

No alcohol

No biscuits, cakes, doughnuts

No jams, spreads - except honey

No coffee, decaffeinated coffee or tea - except herbal teas

No sugar, chocolate or sweets

No artificially produced flavourings: tomato ketchup, vinegar, mustard, etc

Most of the things I like in life are on the proscribed list. Oh, and foods belonging to the nightshade family are banned, too. That means no potatoes, aubergines, cucumbers, tomatoes and peppers. And he wants me to stop smoking, too. He asks if I'm on any drugs. I tell him I've taken Prozac for 10 years. "Eh-hum, OK, so it would be nice if we could get you off the Prozac as well," he says casually.

So what exactly can I eat? Fish (but no tuna or seafood), chicken, brown rice, dark green steamed veg, salad, almonds and walnuts, eggs, soya and tofu, pulses and lentils, buffalo mozzarella; an unfeasible quantity of water (two litres) is not only allowed, it is compulsory. It's life, but not as we know it.

Dr Joshi leads me to a table, asks me to take off my top, and rubs some oil into my back. I am lying belly down on the table. He is about to "cup" me. It's one of his favoured techniques, made famous when Gwyneth Paltrow was photographed with red weals on her back. Apparently, she had forgotten she had been cupped when she chose the backless frock. He explains that it has been used in Egyptian and Chinese medicine for thousands of years for removing impurities from the body - they draw out toxins from your tissues into your circulation. "These cups were actually bought for me by Ralph Fiennes in Moscow." He places the hot, heavy jars on my back. He then leaves me for 10 minutes.

As the minutes go by the jars feel heavier. I wonder where Dr Joshi is, and whether he will ever return. It feels as if I've got a set of burning sink plungers stuck to my back. Come back Joshi. Eventually he returns, and pulls the jars off my back. He warns me that they will leave a mark, but it isn't actually a bruise because it simply fades rather than going black, grey and yellow.

He talks about his life; how he was brought up in Jewish areas of London in Hendon and Edgware by religious Hindi parents, how he went to India to do his medical degree, returned to England to study osteopathy, started to work with dancers, ran an osteopathy practice that serviced every musical in the West End, was introduced to Princess Diana and helped her through her bulimia and depression, turned to complementary medicine, and eventually bought the practice here with the help of his parents. He's a great talker.

Did he ever practise as a conventional doctor? "Not really. Because as soon as I was doing medicine, I was doing osteopathy as well. And I wanted to go in to private practice and be an orthopaedic physician, but it never happened because I just got rollercoastered into looking after dancers."

He cracks my neck with great osteopathic skill and tells me it is extremely stiff and knotted. (He's right - it feels awful.) He then puts a couple of tiny acupuncture needles in my ears and says these will stop my cravings over the coming week. We wander downstairs and he hands me five jars of special Dr Joshi supplements. He tells me to take four of them with meals, and the other one last thing at night. He says barely anything about the supplements beyond their being good for me. He holds one of the jars in front of him. "This is for the P," he stage whispers. "Pardon? "For the P!" he says again. What? "The Prozac!"

Are you serious about me stopping my Prozac just like that, I ask. "Well, maybe you should do it gradually," he says. He books me in for a colonic irrigation following week - an essential part of the cleansing process. I decide that I'm going to give the diet my best shot, but ignore the Prozac advice - I've read too many terrible stories about withdrawal.

Back at work, I lift my shirt and ask a friend if she can see any marks. She screams. I look in the mirror. There are 14 pepperoni-coloured, golf-ball-sized circles on my back. Two neat vertical lines. I look like a lizard. It could be David Beckham's next tattoo. I wander to the local veggie shop to sample my new diet. Wheat-free, gluten-free, yeast-free, taste-free bread is selling for a fiver a loaf. I opt for two packets of budgie seeds and a carrot juice. Love the carrot juice. This is going to be a cinch.

At home I take off my shirt. My younger daughter Maya bursts out crying, asks me what has happened and tells me I'm not her daddy any more. She won't talk to me, won't be in the same room as me. Jesus.

I eat white unflavoured haddock and sweet potato with a banana and a few nuts for afters. I make myself a cup of mint tea - so insipid. I channel-surf the TV manically, while thinking about the bar of Whole Nut I should be eating. Everybody has their own late-night routine, and this is mine - bowl of cereal, bar of Whole Nut, a couple of cups of coffee, occasional cheese and biscuits. I know it's not to be recommended.

Next day, I sleep in till 11am. I just can't get up. There seems to be no point. I should be at work, but can't face it. Eventually, I go downstairs and faff around with Dr Joshi's supplements. I treat myself to an early-morning warm water and lemon, as he recommends. Feel weak and miserable. I eat a banana, munch on a handful of nuts and read his book. I should, I discover, be imagining my new improved self, "someone who leaps out of bed in the morning full of energy and completely in control".

I take myself off to bed and pull the duvet tight over me. Early afternoon I read on. "The person who helped me consolidate my Detox programme was Diana, the late Princess of Wales." In fact, he invented the detox programme for her when she used to visit him at the Hale Clinic. He talks about Cate Blanchett and Kate Moss. Am I the right person for this programme? He is reassuring: "You don't, however, have to be a celebrity to benefit from this detox programme." Phew! The book is full of case histories. I particularly like Janine's story. "Joshi has even given hope that I should not give up finding a lifelong partner," she writes. "I really do feel a new woman."

Day 3

My calves and thighs are aching terribly. Sitting down only makes the pain worse. This is all good, though - Dr Joshi says it's a sign that the toxins are rising to the surface, popping up to say hello. I meet my friend John for supper. Japanese seems to be the only food that can accommodate my dietary requirements. I order chicken, which comes with rice and a sauce. I'm prepared to cheat on the rice and sauce, but John says I'll feel like a fraud. He's eating everything on the menu, and loving it. No afters, no coffee for me. Well, what about retiring to the pub? "But you can't drink," he says. "I'll have water." "But it will be boring for you." I think he means it will be boring for him. We finish our night out at 8.10pm.

Day 4

Ha! The weekend. Time to relax and indulge. Porridge and a handful of supplements for breakfast. Our neighbours have invited us over for lunch. Karen has made something special for me - tomato, mozzarella and avocado salad. Thanks, I say, that's so nice of you, but I'm not allowed tomato or avocado. She asks why not. Because they taste nice is the only answer I can think of. My aches are worse. I wonder how I've managed to eat so many chickpeas and kidney beans and mung beans and haricot beans and butter bleedin' beans without getting diarrhoea. Not for long. I make my excuses and leave. Take the kids out to local art centre in the afternoon. There are gigantic eruptions in my pants. I've never had this before. I stink. I'm a leper. I hate myself.

Day 5

My favourite breakfast. Carrot juice (made from 10 liquidised carrots) followed by two raw carrots. Play tennis with a friend who I have beaten the last two times we played. He hammers me.

Day 6

Singing the Nick Lowe song, Cracking Up, to myself all day. "Cracking up, getting ready to go, had enough of this one-man show... I don't think it's funny no more." Much underestimated artist, Nick Lowe. Why no potatoes in this diet? Potatoes are as natural as they come, salt of the earth, so to speak. Which I'm also supposed to avoid. Alongside pepper. Before Detox Day I had not been longer than a day without chocolate or coffee in adult life and probably not more than three days without alcohol. Hardly smoking because not going to the pub. Feel stoned, without the buzz, withdrawn and miserable. The aches have eased, as Dr Joshi said they would. One of the supplements makes me feel sick. I look at the bottle. In tiny writing is printed, "You should always consult your own physician before starting any dietary regime." Is Dr Joshi now my own physician, or is it my GP?

Day 7

Early for my appointment with Dr Joshi. Walk into a cafe and demand of the waitress whether the yogurt is live and bio something or other and glutenfree. I've become the kind of person I can't stand. "Dunno," says the waitress. "Don't bother if you're worried." I can see what she's thinking - tosser.

How do I feel about alternative medicine? Agnostic, I suppose, but not cynical. Betty the healer, who lives down the road, once cured my broken toe over the phone long-distance when she was in Scotland. Do I believe in healers? Not really, but the evidence was there in the diminished pain and bruising. Acupuncture used to do my headaches good till it stopped doing so. Cupping? Who knows?

Dr Joshi is pleased to see me. He tells me how well I look, and puts me straight on to the scales. He is chuffed. "Look," he says, "amazing, you've lost six pounds." No, four pounds, I say. "Six or four, either way it's very good. Oooh, look at that lovely shape," he says, sliding his fingers down my belly. "You're going to have a six-pack soon."

"I don't want a six-pack," I say petulantly.

He cups me, and then leaves. I feel lonely. I want him to stay with me and talk about my aches. I can hear him chatting downstairs. I'm a bit suspicious. He comes back upstairs. He seems out of breath. I'm very suspicious. No point in beating about the bush, so I come straight out with it: "Have you been cupping somebody else?" He sounds embarrassed, but doesn't try to deny it.

"I feel as if you're two-timing me," I say. "Two-timing you? Hahaha!" Perhaps he's been three-timing me. I bet he didn't leave Diana alone when she was being cupped. Nor Gwyneth.

"The thing is, patients are being rotated around the building - sometimes they are coming to see me for a quick chat - so while you're being cupped I'm seeing them or answering messages on the phone."

These sessions cost £75 per half-hour - the least he could do is stay with me, feign an interest, chat about the weather or the stiffness in my joints. Even better he could ask about the anti-depressants he's told me to stop taking. I could have become a mad axe murderer over the past week for all he knows. Perhaps it's for the best if he's forgotten - I don't need to 'fess up that I've ignored his advice.

He tells me more about his brilliant career as an osteopath in the West End. "In terms of dance injuries, I'm one of the best in the world." The company director of Cats rang him up, amazed, he says, to tell him: "We've been operating Cats for about 17 years and we've never had a full company in the building before."

A spokesman for Cameron Mackintosh later tells me he does remember "a significant increase in people being healthy, but [as for having no injuries] I certainly wouldn't like to make such a claim". Dr Joshi seems to have done so much in his short life - the medical degree, the osteopathy, the dancers, the Hale Clinic, the complementary medicine here in London's Wimpole Street. How old are you, I ask. "In my early 40s," he says, fluttering his eyelids, "I know... I don't look it." Well, you do and you don't, I think to myself. Sure, he has a baby face, but he also has receding greying hair and an incipient paunch.

He takes the acupuncture needles out of my ear and replaces them with new ones. He wears three rings on his fingers - ruby and diamond, emerald and gold. "Ayurvedically and in the Hindu religion, certain stones are supposed to be good for you."

How did he get to run this posh clinic? "I decided with my family's help to buy my own building." They must be loaded, I say. "Yeah, but I look after a lot of important people. Everybody thinks about the stars, but you know one of my patients in Europe used to fly me on Concorde when it was around - just for an hour." From the rich, he segues into an anecdote about the famous. "Kristin Scott Thomas's just about to start a play, and she was sent by her director. She came to see me on Friday with a raging fever. She couldn't believe it, on Sunday she got up and felt fine."

What did he do for her? "I just cupped her twice and gave her some of my herbal tonics. The director Jonathan Kent has worked with me for years - in the middle of rehearsals if anybody as much as coughs, he'll shout, 'Joshi, can somebody get Joshi?' I look after a lot of the international royal families and I do run a very private discreet practice." He pats me on the knee, indicating it's time to go.

Dr Marina Chernova, the colonic irrigationist, works from the top floor of the clinic. She is middleaged, and has a strong accent I couldn't place. In no time I am lying back on a table with a great tube up my bottom, and Dr Chernova is showing me the liquid passing through her machine. There is no smell. It is perfectly sanitary. And after the initial shock, it feels rather nice - warm and bubbly liquid shoots up me. She tells me to let go. I do. It's like being back in nappies, only there's no nappy, just a tube and Dr Chernova massaging my stomach into action. I tell her that a few people advised me not to have colonic irrigation because it removes all the good stuff as well as the bad. "Are they doctors?" she asks. "Are they scientists?" I shake my head as best I can while prostrate. "Exactly," she says.

Day 8

"Freak," Maya says, forgetting she's not talking to me. Diane, my partner, who normally eats so healthily that she must be virtually toxin-free, has started eating chocolate. She says she doesn't like what has happened to me; that it's taken the ground from under her feet. On the plus side, my aches have gone, as Dr Joshi said they would.

Day 9

Stopped listening to music. Not had the energy or desire. Have discovered that white fish tastes OK with hummus. Dr Joshi is in the news for treating Kylie. It makes me feel kind of special.

Day 10

Have become socially dysfunctional. I've got only one topic of conversation. My detox. Actually, two - the diet and my cupping. And the colonic, which makes it three.

Day 11

Weekend. I'm sure I slept better when I was pumped with coffee. We're going out tonight to friends for supper. Should be embarrassing when I snub their food. Only celebs can a) get away with such antisocial behaviour, b) afford to have people cook them nice dishes from such limited ingredients. Luckily, friends suggest a restaurant and with a mild cheat I get away with it - chicken and white rice. Real food. Yum!

Day 12

Have a sushi lunch. Only two weeks ago I would have had sushi and been hungry again within five minutes. My stomach must have shrunk. Kylie has issued a statement saying she is not seeing any complementary doctors to help with her cancer.

Day 13

Interview pop star Pete Doherty and tell him I'm detoxing. Feel such a wuss when he asks what from, and I say coffee and alcohol and carbs and fruit except for bananas.

Day 14

First time ever in a pub without drinking alcohol. I last around 20 minutes and leave my water unfinished.

Day 15

Exhausted and bad-tempered. Any weight I've lost this week has been from my face. Friends say I look gaunt and yellow. Maybe it's the carrots. Even Dr Joshi says I don't look too clever. He leads me to the scales. I've lost a couple of pounds. He's got a treat in store. "Today we're going to help balance all your meridians. We're going to do acupuncture today ... See, it doesn't hurt at all."

No, but my neck does, it's locked again. I wish Dr Joshi would give my neck a good cracking - I don't mention it to him, but I would have thought it was obvious.

There's a photo of Dr Joshi on the mantelpiece. He's holding up two Persian cats in front of him, which makes him look like he's wearing a doubleheaded fur stole. Dr Joshi used to be married, and has a nine-year-old daughter, but now he lives alone with the cats (Tom and Jerry) and a housekeeper.

I ask about his relationship with Diana. He tells me how she would visit him at the clinic for lunch to discuss life and how he came to invent the detox for her. She was bulimic at the time. "I started changing her diet and making her feel better in herself and making her skin look better and she lost weight and she certainly became amazing looking." You were responsible for making her amazing looking? "Partly, yeah." Joshi regards Diana as a visionary. He talks of her with reverence and love. "It was Diana who told me, try to do as many principles and philosophies as possible, and try to become much more integrated in my approach. And also, try to see how you can offer people with asthma not just inhalers - any idiot can do that - but see how you can treat asthma with breathing exercises; rather than giving people a laxative, give them a dietary change. Try and get rid of migraines not with painkiller but by seeing if there's a sugar intolerance."

I ask why he has so many famous patients. "Word of mouth. Somebody is feeling better and if they are at a dinner party they say, 'Oh, I know just the man you've got to see', and they respect me and they like me as a person, and they know that I'm a genuine guy. It's lovely - one of my famous lady patients was doing a movie and I got a call from her saying, please, could you come and see another very famous Oscar-winning actress because she's got this terrible headache. And I had to go and treat her in a caravan in the middle of Sainsbury's car park off Finchley Road."

Who was it? "Don't say ..." Then he stage whispers, "Judi Dench and Cate Blanchett."

How was he affected by Diana's death? "I was quite devastated," he says quietly. He starts blinking. "And you know I've kept my whole association with her very private. I've never tried to associate myself with her at all..." As a young man, he quit his medical degree course in India after three years, and it was Diana who encouraged him to return to complete it, so he had a conventional medical qualification behind him. It was as if she was leading him back to India.

Why did he quit his degree in the first place? "I was a bit disillusioned with the way medicine was going. I wanted to go into treating orthopaedic injuries and I just felt the whole attitude was more towards painkillers and steroid injections and surgery and whatever. I was very interested in osteopathy at the time and I thought it was a much more holistic approach to patients' health." He spent four years studying for his diploma at the British School of Osteopathy.

He finishes the acupuncture and tells me I'm looking great. He removes every needle except the two tiny ones in my ears. "Aren't you feeling healthier?" I tell him I'm feeling weak. "How do you feel your body has changed? Before, you needed the coffee to get you going in the morning, didn't you? And now you don't need that. You manage to get going. So your body's ability is kicking in. Do you feel there's any deprivation?"

No, I say, I think it's amazing that I've been able to give up all these things with so little sacrifice, but I still feel crap. How does your editor feel you look? "She thinks I look tired." "Really?" he says, dismayed. "Does she feel you're looking better from the detox generally? I think you're looking thinner. Also, you've got better colour in your skin. And your eyes look a bit clearer." They are actually bloodshot today.

"I think you'll have a bit of a struggle first thing in the morning anyway for somebody who has had a coffee addiction. But if I was to see you at 6pm, I bet you'd be on all four cylinders. Yep." He looks at his sheet and asks about my headaches and sweats and depression. But not the antidepressants.

After the three weeks, he says, if I stick to his diet 80-90% of the time, and just indulge myself with the occasional pizza or coffee, I'll feel great. "When you next go to the Ivy, you're more likely to pick things that are good for you." Who mentioned the Ivy?

As I leave I ask him what the truth is about Kylie - one day I read she's seeing him, the next she's not. "Well, I think fundamentally, on record, it's better that she's not coming to Dr Joshi."

Day 16

I discover almond butter. What a find!

Day 17

I'm sick of diarrhoea. I reckon I could do my day's calories in a 15-minute tea break - half a jar of almond butter (800 cals), half a dozen oat biscuits, a packet of Food Doctor Seed Mix, half a packet of almonds. Bob's your uncle, 2,000 calories.

Day 18

The neighbours are back from holiday. They bring me back a huge brick of parmesan. Bastards.

Day 19

I speak to Edzard Ernst at Exeter University, the country's only professor of complementary medicine. What does he think about taking people off anti-depressants? "Taking a person off anti-depressants requires careful consideration indeed. It is a dangerous process - there's a real risk of suicide. So it has to be carefully supervised."

What about cupping? "It falls under the umbrella of counter-irritation. You irritate the skin so you might give benefit in terms of pain control. Any medical claim is not supported by evidence. It's nonsense that it brings toxins to the surface. I am really upset about practitioners who give irresponsible advice to patients, because they threaten everything that is good in complementary medicine."

What advice would Professor Ernst give people seeking a complementary practitioner? "Make sure that practitioner is registered with a professional body of high standing. Next, I would always tell your GP and listen to his advice carefully." If you decide to see a complementary practitioner, he suggests, you should get a full treatment plan including diagnosis, prognosis and treatments; ascertain the practitioner's experience, the proven risks and benefits of the treatments, any alternative treatments, and the price.

Day 20

Feeling demob happy, even though my left ear is hurting and feels swollen. The receptionist at Dr Joshi's practice says that the tiny acupuncture needles should have been taken out after a week, and if I can't pop down to the surgery, she recommends I take them out myself.

Day 21

Liberation. I'm grinning manically at Dr Joshi. He weighs me. I've lost half a stone over the three weeks. Which is nice, whatever the kids say. But as for feeling fresh and revitalised, I don't. I'm just exhausted. What have I discovered about myself? It is good to be less toxic, but ultimately I think this diet is primarily a means to radical weight loss that likes to think of itself as something superior and scientific. And the headaches, sweats and depressions? Exactly the same, thank you very much.

We talk about the difference between conventional and complementary medicine, and I ask him why he bothered to complete his medical degree after Diana died when he never intended to practice. Well, he says, it just felt right, he trusted her advice. "And because it gives you a certain amount of credibility in the western world."

Dr Joshi is qualified to practise conventional medicine in India, but he is not registered with the GMC here (which would require him to take two exams and work in an NHS hospital). However, he is registered with another professional body of high standing - the General Osteopathic Council. I ask the GOC what it thinks about osteopaths referring to themselves as doctor. A spokesperson refers me to clause 126 in its code of practice. "Unless you are a registered medical practitioner [ie, with the GMC], you must not use any title that implies that you are a medical practitioner."

But Dr Joshi insists it would have been pointless to register with the GMC. Why? "Because you can't work in a holistic way and in a natural way - they don't allow that to happen any more." You can't practise conventional medicine and complementary medicine, I ask, astonished. "You can't do both, yep. You can do one or the other." It's a strange thing for him to say. After all, integrated medicine, whereby GPs offer complementary therapies, is so fashionable today.

The GMC is surprised by Dr Joshi's statement. A spokesperson says: "The GMC does not prohibit doctors on its register from practising in complementary or alternative medicine. We are aware of many doctors on our register who offer both alternative and conventional treatments. We do say that doctors should be up to date in their skills and knowledge, and offer patients the treatment that is in their best interests."

A couple of days after completing the detox, I ask Dr Joshi how long he normally leaves the acupuncture ear needles in for. "Five to 10 days," he says. So why did he leave mine in for two weeks? "What I always recommend patients when I put these in is that we're going to keep them in for five to 10 days, when I normally expect patients to take them out themselves." He must have forgotten to tell me that.

And why did he only look at my neck once when Iwas obviously in some pain? "The first time I did it, I did it because it was going to kickstart the whole detox process, and it was going to give it a bit of a boost. It's like giving somebody 10,000 milligrammes of vitamin C when they are about to get a cold."

And how does he answer those who say there is no scientific basis to cupping? "My answer to them is that a lot of things in modern medicine are not proven as well. They produced a wonderful drug called Vioxx a few years ago, which was thought to be the new wonder drug for arthritic pain, and it had to be taken off the market about 18 months ago because it was found to increase your chance of getting a stroke by 30%. Up until about 50 years ago osteopathy wasn't proven."

Finally, I ask about the pills he prescribed as an alternative for Prozac. "5htp, hydroxytryptophan, an amino acid, which helps balance your serotonin and dopamine level, and Prozac is the chemical version of that," he says instantly. So why didn't he follow up on my Prozac withdrawal? "Two reasons: I didn't probe much more into the antidepressant side because it's a long-term condition with you, and you were doing this for three weeks and I didn't want to destabilise your whole medical system. If you would have been coming to do a whole long-term project with me to actually come off the Prozac, then I would have liaised with your GP, explained what I was going to do and then we would have taken you off it slowly." That's fine, but it doesn't really explain why he gave me the 5htp, which I took.

Perhaps it would be best if Dr Joshi drops the Dr and returns to simple Joshi, despite his medical training. Whatever - he is charming, a good businessman and obviously has a winning bedside manner with celebrities. As for me, I hope I do manage to cut down on the nasties, and think there's every chance. After four half-hour sessions, at a cost of £400, I'm chuffed that I did manage to give up so many things that I've always regarded as indispensable. A couple of people have me I'm looking well. As for the promise that I'd find chocolate disgusting after abstaining for three weeks, there's only one way to find out. I buy myself a huge eight-chunk bar of Whole Nut, and devour it in one. Ah, wonderful.